https://github.com/torvalds/linux
Revision b3656d8227f4c45812c6b40815d8f4e446ed372a authored by NeilBrown on 26 February 2021, 01:22:25 UTC, committed by Linus Torvalds on 26 February 2021, 17:41:05 UTC
Patch series "Fix some seq_file users that were recently broken". A recent change to seq_file broke some users which were using seq_file in a non-"standard" way ... though the "standard" isn't documented, so they can be excused. The result is a possible leak - of memory in one case, of references to a 'transport' in the other. These three patches: 1/ document and explain the problem 2/ fix the problem user in x86 3/ fix the problem user in net/sctp This patch (of 3): Users of seq_file will sometimes find it convenient to take a resource, such as a lock or memory allocation, in the ->start or ->next operations. These are per-entry resources, distinct from per-session resources which are taken in ->start and released in ->stop. The preferred management of these is release the resource on the subsequent call to ->next or ->stop. However prior to Commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") it happened that ->show would always be called after ->start or ->next, and a few users chose to release the resource in ->show. This is no longer reliable. Since the mentioned commit, ->next will always come after a successful ->show (to ensure m->index is updated correctly), so the original ordering cannot be maintained. This patch updates the documentation to clearly state the required behaviour. Other patches will fix the few problematic users. [akpm@linux-foundation.org: fix typo, per Willy] Link: https://lkml.kernel.org/r/161248518659.21478.2484341937387294998.stgit@noble1 Link: https://lkml.kernel.org/r/161248539020.21478.3147971477400875336.stgit@noble1 Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: NeilBrown <neilb@suse.de> Cc: Xin Long <lucien.xin@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tip revision: b3656d8227f4c45812c6b40815d8f4e446ed372a authored by NeilBrown on 26 February 2021, 01:22:25 UTC
seq_file: document how per-entry resources are managed.
seq_file: document how per-entry resources are managed.
Tip revision: b3656d8
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arch | ||
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certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 18.5 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 98.3 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 576.3 KB |
Makefile | -rw-r--r-- | 64.5 KB |
README | -rw-r--r-- | 727 bytes |
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